연약지반 방파제의 시공성능 및 장기침하에 관한 실험적 평가

권오순,장인성,박우선,염기대,Kwon, O-Soon,Jang, In-Sung,Park, Woo-Sun,Yum, Ki-Dai 한국해양과학기술원 2003 Ocean and Polar Research Vol.25 No.suppl3

A new type of soft ground breakwater was recently developed, which does not need ground improvement because of light weight and structural characteristics. The various studies about consolidation settlements and lateral behavior of proposed soft ground breakwater have been conducted. But, the systematic investigations on the construction performance and long-term settlements of new type breakwater has not been accomplished. In this study, construction simulation of soft ground breakwater with soil box model test and experiments of the long-term wave loaded breakwater were performed. The results of test shows that it is possible to compensate differential settlements by dead loading and/or suction pressure, and to reduce the consolidation settlements by preloading method. It was also found that the vertical and lateral displacements of long-term wave loaded breakwater were negligible.

MOSFET를 이용한 고효율 SCALDO 레귤레이터 구현

권오순,손준배,김태림,송종규,Kwon, O-Soon,Son, Joon-Bae,Kim, Tea-Rim,Song, Jong-Gyu 한국전기전자학회 2015 전기전자학회논문지 Vol.19 No.3

A SCALDO(Supercapacitor Assisted LDO) regulator is a new regulator having advantages of a SMPS(Switch Mode Power Supply) which has a good efficiency and a LDO(Low Drop-out) regulator which has stable output characteristics and good EMI(Electro Magnetic Interference) characteristics. However, a conventional SCALDO regulator needs a lot of power consumption to control its switches and it drops an efficiency of the circuit. In this paper, to reduce switching power consumption and improve an efficiency of the circuit, a new SCALDO regulator adopting MOSFETs as its switching parts is proposed and it is found out that the proposed SCALDO regulator has the maximum 9.5% higher efficiency than the conventional SCALDO regulator. We also try to simplify production process of the circuit by changing switching control method of the circuit from MCU(Micro-controller unit) based firmware control to hardware control using a comparator and a T-F/F(Flip Flop). SCALDO(Supercapacitor Assisted LDO) 레귤레이터는 기존에 널리 사용되고 있는 SMPS(Switch Mode Power Supply)의 장점인 높은 효율과 LDO(Low Drop-out) 레귤레이터의 장점인 안정적인 출력 및 우수한 EMI(Electro Magnetic Interference)특성을 함께 가지는 레귤레이터로 현재 새롭게 연구되고 있는 전원회로이다. 하지만, 현재까지 연구된 SCALDO 레귤레이터의 경우 회로 내부의 스위치제어에 많은 전력이 소비되어 회로 전체의 효율이 감소되는 단점이 있다. 본 논문에서는 기존 SCALDO 레귤레이터의 단점을 극복하고 저전력으로 구동이 가능한 MOSFET를 SCALDO 레귤레이터에 적용함으로써 스위치제어 소비전력을 최소화하여 회로 전체의 효율을 향상시킨 새로운 SCALDO 레귤레이터를 구현 하였으며, 기존 SCALDO 대비 효율이 최대 9.5% 상승됨을 확인하였다. 또한 기존의 MCU(Micro-controller unit)를 이용한 펌웨어제어를 비교기 및 T-F/F(Flip Flop)을 이용한 하드웨어 제어로 대체함으로써 회로의 제작과정을 단순화 하였다.

감정평가액 편차 극소화를 위한 수목분류의 방법과 절차

권오순 ( Oh Soon Kwon ),최형석 ( Hyung Seok Choi ) 한국감정평가학회 2009 감정평가학논집 Vol.8 No.2

This article describes that the choice of taxa would be important at a woody plant classification with researching taxonomic character and character state. The writers of this article also found that confirmation of taxonomic character and character state was more important than that of choosing taxa. In that sense, appraisers should confirm the taxonomic character and character state, before they appraise a woody plant of which they found a double-faced character in a woody plant classification. If the method and process of a woody plant classification mentioned in this article are applied to a woody plant appraisal, there are not remarkable deviations among the various appraisal amounts of a woody plant appraisal. It was found that the deviation of appraisal amounts was remarkable between the appraisal amount of a pine tree classified as a landscape tree and that of a pine tree classified as a standing(timber) tree. It was also found that the deviation of appraisal amounts was remarkable between the appraisal amount of a persimmon tree classified as a landscape tree and that of a persimmon tree classified as a fruit tree. It is sensible of appraisers to realize that each of those two woody species has a double-faced character of a woody plant in a woody one classification. Authors sincerely hope that the method and process of a woody plant classification mentioned in this article will be accepted as a general standard of a woody plant appraisal.

감정평가액 편차의 허용한계와 그 비율의 관념 및 활용방안에 관한 고찰

권오순 ( Oh Soon Kwon ) 한국감정평가학회 2009 감정평가학논집 Vol.8 No.1

The writer researched the types of inevitable deviation in real property appraisal in view of the gap of value against price, the multiplication-of-value concept and the cause of valuation system involved. It was scientifically turned out that the application of the tolerance limit and its ratio could resolve the problems regarding the inevitable deviation of appraisal amounts mentioned above in real property valuation. The upper limit of tolerance limit and the lower limit of it would be defined as ‘tolerance limit ratio.’ Tolerance limit and its ratio might be known as a terminology newly developed. If the deviation which is generated among various appraisal amounts distributes within the scope of the tolerance limit, there are not remarkable differences among the various appraisal ones. After all, tolerance limit and its ratio will be able to become a guide line for appraisers to find the remarkable differences among various appraisal ones.

잔교식 안벽의 내진성능 평가 및 개선(Ⅰ) : 고유 진동모드 관점에서

권오순(Kwon O-Soon),장인성(Jang In-Sung),박우선(Park Woo-Sun) 대한토목학회 2002 대한토목학회논문집 B Vol.22 No.3B

연약지반 방파제의 압밀 침하 거동

권오순(Kwon O-Soon),장인성(Jang In-Sung),박우선(Park Woo-Sun),염기대(Yum Ki-Dai) 대한토목학회 2002 대한토목학회논문집 B Vol.22 No.1B

사전충전모드를 통한 SCALDO 레귤레이터의 초기 동작특성 개선

권오순(O-Soon Kwon),손준배(Joon-Bae Son),송종규(Jong-Gyu Song) 한국전기전자학회 2016 전기전자학회논문지 Vol.20 No.3

SCALDO(Supercapacitor Assisted LDO) 레귤레이터는 기존 LDO(Low Drop-out) 레귤레이터(이하 LDO)의 낮은 효율을 개선하기 위해 연구되고 있는 회로로서, 회로의 입력단과 LDO사이에 슈퍼커패시터를 부착하여 입력과 출력전압의 차이에 의해 발생하는 불필요한 전력손실을 재사용함으로써 LDO의 효율을 향상시킬 수 있다. 하지만 SCALDO 레귤레이터는 현재 연구 중에 있는 회로로 몇 가지 개선되어야 할 사항들이 남아있다. 그 중 한 가지는 회로의 최초동작 시 LDO에 인가되는 과전압문제이다. 회로의 최초동작 시 슈퍼커패시터가 완전히 방전되어 있어 충전모드 시 입력과 슈퍼커패시터, LDO가 직렬로 연결되는 SCALDO 레귤레이터 특성 상 입력전압이 LDO에 짧은 시간동안 그대로 인가되는데, 입력전압이 출력전압보다 최소 2배 이상 크기 때문에 이는 LDO에 상당히 큰 부담이 될 수 있다. 본 논문에서는 이러한 과전압 문제를 해소하기 위해 회로 동작 전 슈퍼커패시터를 충전시킬 수 있는 사전충전부가 포함된 새로운 SCALDO 레귤레이터를 제안하였으며, 실험을 통해 동작 초기 LDO에 인가되는 과전압이 상당부분 감소됨을 확인하였다. A SCALDO(Supercapacitor Assisted LDO) regulator is a newly studied regulator to improve the efficiency of a LDO regulator. Commonly a LDO regulator has very low efficiency and a SCALDO regulator can improve it considerably because this regulator can reuse meaninglessly wasted energy at the LDO regulator by a supercapacitor witch is attached between input and a LDO regulator. However this regulator has several challenges because it is a being studied regulator. One of them is an overvoltage issue. At initial operating of this regulator, a supercapacior is totally discharged and input is connected with a supercapacitor and a LDO regulator in series. Thus, input voltage is enabled to a LDO regulator and this input voltage is a significant value to a LDO regulator because commonly input voltage is bigger than twice output voltage. In this paper, to solve this overvoltage issue, we proposed a new SCALDO regulator that has a pre-charger for charging a supercapacitor before starting operation. And we found that a proposed SCALDO regulator can properly reduce overvoltage of a LDO regulator through experiments.

잔교식 안벽의 내진성능 평가 및 개선(Ⅱ) : 시간이력해석 관점에서

권오순(Kwon O-Soon),장인성(Jang In-Sung),박우선(Park Woo-Sun),조성민(Cho Sung-Min) 대한토목학회 2002 대한토목학회논문집 B Vol.22 No.4B

신형식 연약지반 방파제에 대한 1차원 압밀이론의 적용성 평가

권오순(Kwon O-Soon),장인성(Jang In-Sung),박우선(Park Woo-Sun),염기대(Yum Ki-Dai) 대한토목학회 2002 대한토목학회논문집 B Vol.22 No.6B

상부단면 확대형 해상 말뚝의 개발

권오순(Kwon, O-Soon),장인성(Jang, In-Sung),권영호(Kwon, Young-Ho),기민주(Ki, Min-Joo) 한국해안해양공학회 2009 한국해안해양공학회 논문집 Vol.21 No.6

해양에서는 횡방향 하중에 의해 구조물 기초의 설계가 좌우되기 때문에 이 연구에서는 기존의 말뚝 기초 공법보다 횡방향 지지력이 크고 시공성능이 우수한 새로운 형식의 말뚝 기초 공법을 제안하였다. 제안한 기초에 대한 성능을 평가하기 위하여 수치해석을 수행하였으며, 기존 항만 현장 조건에 대입하여 설계를 수행하여 시공 특성과 재료비 감소 효과를 통한 경제성 평가를 수행하였다. 연구에서 강관말뚝에 비해 횡방향 지지력의 증가를 확인하였으며, 기존 공법과 비교하여 공사비용은 62~80%정도로 평가되었다. In this study, new type of pile foundation was introduced for the better performance of lateral resistance than conventional piles by adopting enlarged upper section, because offshore structure design is subjected to the lateral loading. The numerical simulations were peformed in order to find out the lateral behaviour of the proposed pile. The economical efficiency of new pile system was also analyzed by considering the construction characteristics and material costs as well as the real field condition of harbor sites in Korea. From the study, it was revealed that the lateral resistance of piles with enlarged upper section is increased compared to conventional steel pile, and the construction costs would be reduced to about 62~80% of previous methods.